The present invention relates to a device for composting organic material, such as poultry carcasses, and in particular to a device which minimizes handling operations by combining the functions of a mobile composter with a spreader for land application of composted material.
Poultry growing necessarily results in the deaths of some proportion of the birds. In a large poultry growing operation, the numbers may exceed some hundreds of birds per day on an average basis. The disposal of the carcasses presents a considerable problem to growers. One solution has been to bury the carcasses. This solution has a number of problems, not the least of which is the environmental impact. Present and anticipated environmental regulations will severely limit or curtail this practice. Alternatives to burying include incineration and composting. Incineration is costly and otherwise undesirable. Composting appears to be a practical, cost effective, and environmentally acceptable method of disposal of poultry carcasses. Composting is a well known art in which organic material is decomposed to produce an environmentally benign and useful soil amendment. Composting can destroy pathogens and is well suited to the disposal of animal carcasses.
One well known technique of composting is to place the organic material in a pile, such as a windrow, or in an enclosure with suitable amendments to enhance the natural biological processes that break the organic material down into a humus for application to the soil. It is known to use such a process for poultry carcasses. U.S. Pat. No. 5,206,169 issued to Bland on Apr. 27, 1993 discloses a compost crib for composting chicken carcasses. The apparatus of Bland is not mobile and contains no provision for spreading the composted material.
Turning the material at intervals during the composting process is well known. Horizontal rotary composting drums for this purpose are disclosed in U.S. Pat. Nos. 5,300,438; 5,589,391; and 3,942,769.
Most composters, including the rotary types, are intended to be stationarily mounted. It is known however to mount a rotary drum composter on wheels for mobile operation. U.S. Pat. No. 5,300,438 issued to Augspurger et al. discloses a horizontal rotary drum composter which may be mounted on a two wheeled trailer for mobile operation. Other patents for composters that are mobile or portable include small composters for domestic use such as Petzinger, U.S. Pat. No. 4,105,412, or composting machines designed to be employed in turning windrows of composting materials, such as Urbanczyk, U.S. Pat. No. 4,019,723. Also disclosed is a portable compost grinder, U.S. Pat. No. 3,850,364. U.S. Pat. Nos. 5,547,420 and 5,076,504 disclose mobile devices for pulverizing animal carcasses to prepare the material for composting among other purposes. Neither patent is specifically for an apparatus or method of composting.
Although horizontal rotary drum composters are suitable for composting poultry carcasses, the significant limitation to the use of composting in the disposal of poultry carcasses is not the technology of composting per se, but the material handling problem of dealing with large numbers of carcasses on a daily basis, including transferring the carcasses from poultry house to composter, transferring the composted material to a land disposal site, and finally spreading the composted material on the land disposal site. Typically, the following operations are required: poultry carcasses are collected from poultry houses and placed into some form of transport vehicle, the transport vehicle transports the poultry carcasses to a composting facility, the carcasses are loaded into the composter, and, after a suitable period of composting, the composted material is removed from the composter, loaded onto a transport vehicle, carried to a land disposal site, transferred from the transport vehicle to a mobile spreader, and the spreader then applies the composted material to the land. The large number of handling operations are inefficient and time consuming. Employing a mobile composter could alleviate some of the handling operations, although the present inventor is not aware of any suggestion in the prior art that a mobile composter would be useful in alleviating the handling problems involved in the disposal of poultry carcasses. Even the employment of a mobile composter does not alleviate all the handling problems, however, since the composted material must still be transferred from the composter to the spreader, which involves potentially two additional handling operations. To the knowledge of the present inventor, the prior art does not suggest the combination of a mobile composter with a spreader to avoid these additional handling operations.
The problems and limitations of the prior art are overcome by the present invention as summarized below.